Detector device for a blade tracking system having two sensors

ABSTRACT

The device relates to a detector for a blade (30) tracking system which detector comprises lens means (11) for focusing in a plane (14) a bundle of radiation passing therethrough characterised in the two or more radiation sensors (21,22) are disposed within said plane, the arrangement being such an object (30) being sensed passing through the radiation bundle is sensed sequentially by said sensors.



